1. Field of the Invention
The present invention relates to an electric connector and, more specifically, to a combination connector shell for electric connector, which is comprised of a front housing, a rear housing, and a terminal holder that are connected to one another by hook joints and prohibited from horizontal and vertical displacement relative to one another.
2. Description of the Related Art
Following fast development of computer technology, various versatile electric connectors are developed for signal transmission in computer networks. For example, an electric connector may be provided with a LED indicator circuit to indicate different signal transmission status or failure of the circuit. Regular RJ45 connectors are commonly used for digital communication. These connectors generate high frequency electric waves that interfere with surrounding electric apparatus. Further, the internal transmission signal tends to be interfered noises produced in the external cable. In order to eliminate EMI (electromagnetic interference), a metal shield or filter module may be used. When a filter module is used, the filter module must be installed within the circuit board and the terminal holder in the electrically insulative housing. After installation, the positive connection between the housing and the terminal holder and the electric connection among the terminals, the filter module and the circuit board must be well checked, assuring accurate signal transmission.
FIGS. 10 and 11 show an electric connector according to the prior art. According to this design, the electric connector comprises a first terminal holder B holding a set of first terminals B1, a second terminal holder D holding a set of second terminals D1, an electrically insulative housing A adapted to accommodate the terminal holders B and D, the insulative housing A having two backward hook arms A1, a circuit board C to which the first terminals B1 and the second terminals D1 are soldered, the circuit board C having two side notches C1 and C2 respectively forced into engagement with the hook arms A1, and a metal shield E covering the housing A. This structure of electric connector has drawbacks. When soldering the terminals B1 and D1 to the circuit board C, the terminal holders B and D interfere with the soldering operation. Further, simply using the hook arms A1 to hold the circuit board C cannot prohibit vertical displacement of the circuit board C relative to the insulative housing A.
FIGS. 12 and 13 show another structure of electric connector according to the prior art. This structure of electric connector is comprised of an outer housing, an inner housing, and a terminal holder. The main advantage of this structure of electric connector is its detachable structural design, i.e. either of the outer housing, the inner housing and the terminal holder is replaceable when damaged. According to this design, the connection of the terminal holder with the terminals and the circuit board is complicated. The terminal holder is inserted into the inner housing and then the outer housing after installation of the circuit board in the terminal holder. The hook joint between the terminal holder and the inner housing cannot prohibit vertical displacement of the terminal holder relative to the inner housing and the outer housing. Further, it is difficult to solder terminals to the circuit board within a limited space.
Therefore, it is desirable to provide a combination connector shell for electric connector that eliminates the aforesaid drawbacks.
The present invention has been accomplished under the circumstances in view. According to one aspect of the present invention, the combination connector shell comprises an electrically insulative front housing adapted to hold first terminals, an electrically insulative rear housing abutted against the rear coupling side of the front housing, a terminal holder attached to the bottom side of the rear housing and adapted to hold second terminals, a second coupling structure adapted to lock the rear housing to the front housing, and a first coupling structure adapted to lock the terminal holder to the rear housing. According to another aspect of the present invention, the terminal holder has a top receiving space adapted to accommodate a circuit board, for enabling a filter module and other electronic component parts as well as the first and second terminals to be conveniently soldered to the circuit board. According to still another aspect of the present invention, the terminal holder further comprises two stop rods bilaterally extended from the front side for insertion into insertion slots in the front housing to prevent horizontal displacement of the terminal holder relative to the front housing.